Capt Nemo -
Nice setup - Is this the same unit I saw in the homebuilt fluid bed thread?
How many watts is your solar array and how much time does it extend your battery run time?
I am assuming this is a picture of Lake Superior. What can people expect when they prospect and mine there?
Are the black sand concentrations fairly high like on the west coast beaches?
Yes it is. I've built 8 different beds, and so far model 4,5,7, and 8 have been successful. It's a Coleman 55 watt solar panel system running a 36 watt 800 GPH bilge pump, so I can run all day. The model 5 (highbanker) runs 3 of those pumps, so I added a second panel set and larger charge controller.
When prospecting there expect your location to change daily. In one day you can watch the beach at the waterline to go from cobble to sand and back again. Stuff is really moving around there. You may find a lens of black sand about 12" down, or it could be at the surface. Bands can be 2-3" thick, but if you're lucky you can get a patch 12" thick or more. There's a lot of fine black pea gravel that's also magnetic, and the black sand can also be found in buried cobble. So far, gold has run from #16 mesh (windowscreen) on down, but a nugget may be possible but rare. I've seen values run up to 1.5 grams per yard. Run anything 1/8" or less. The black sand is a sure bet, but anything there may be gold bearing, as the waves move everything around a lot. Right now I'm running a patch (hopefully it's still there) of black sand that varies from 1/4" to 3" thick and is 100 yards long. It was pushed way up the dune by the waves. A 3.5 gal bucket of that netted 40 pieces from #16 on down, and the panned out cons and tailings seem to have a heavier material than iron sand. I'm about to have a sample tested to see what else is in it. I have found platinum there every once in awhile, and copper, silver, and electrum are also possible. And search the cobble for agates! Rock pickers abound. The State of Michigan does not recognize any mineral claim beyond the high water mark, and if you have come down a cliff or steep eroded bank to get to the beach, the base is the high water mark. Recirculating systems will prevent the need for a pump permit. Bag limit on gold is 1/2 oz per year. (but who's going to check a bucket of cons for it)
Safety note. If the waves are running at an angle to the beach, STAY OUT OF THE WATER!!! Alongshore currents can do 15-20 MPH, and move 8" rocks with ease. Always watch the water for a rogue wave. Moose, wolves, coy wolves, and black bears are also possible.
